Twenty-five years ago, when the Big 3 television networks ruled the airwaves, audience measurement firm Nielsen Co. introduced a gizmo called "people meters" that revolutionized the television industry.
Instead of relying solely on the diaries that members of "Nielsen families" filled out by hand, listing the shows that they watched, the device provided a more efficient and accurate way to measure who was watching what shows and when. Diary results were always suspect because procrastinators often waited until the end of the month-long "sweeps" periods, typically November, February and May, to fill out the diaries.
But with the introduction of people meters into 2,000 homes in 1987, the networks suddenly got overnight ratings results.
The updated measurement technique made the TV business more competitive. It became more difficult for network executives to be patient with shows, allowing promising ones time to gain traction.
The devices also accelerated the trend of advertisers zeroing in on key demographics, such as viewers 18 to 49. Shows that appealed to younger audiences became more valuable than shows that had older-skewing audiences.